Merge branch 'pw/single-key-interactive'

The single-key interactive operation used by "git add -p" has been
made more robust.

* pw/single-key-interactive:
  add -p: disable stdin buffering when interactive.singlekey is set
  terminal: set VMIN and VTIME in non-canonical mode
  terminal: pop signal handler when terminal is restored
  terminal: always reset terminal when reading without echo

add-interactive.c

@@ -70,6 +70,8 @@ void init_add_i_state(struct add_i_state *s, struct repository *r)
 			      &s->interactive_diff_algorithm);
 
 	git_config_get_bool("interactive.singlekey", &s->use_single_key);
+	if (s->use_single_key)
+		setbuf(stdin, NULL);
 }
 
 void clear_add_i_state(struct add_i_state *s)

compat/terminal.c

@@ -11,7 +11,7 @@
 static void restore_term_on_signal(int sig)
 {
 	restore_term();
-	sigchain_pop(sig);
+	/* restore_term calls sigchain_pop_common */
 	raise(sig);
 }
 
@@ -31,14 +31,20 @@ void restore_term(void)
 	tcsetattr(term_fd, TCSAFLUSH, &old_term);
 	close(term_fd);
 	term_fd = -1;
+	sigchain_pop_common();
 }
 
 int save_term(int full_duplex)
 {
 	if (term_fd < 0)
 		term_fd = open("/dev/tty", O_RDWR);
+	if (term_fd < 0)
+		return -1;
+	if (tcgetattr(term_fd, &old_term) < 0)
+		return -1;
+	sigchain_push_common(restore_term_on_signal);
 
-	return (term_fd < 0) ? -1 : tcgetattr(term_fd, &old_term);
+	return 0;
 }
 
 static int disable_bits(tcflag_t bits)
@@ -49,12 +55,16 @@ static int disable_bits(tcflag_t bits)
 		goto error;
 
 	t = old_term;
-	sigchain_push_common(restore_term_on_signal);
 
 	t.c_lflag &= ~bits;
+	if (bits & ICANON) {
+		t.c_cc[VMIN] = 1;
+		t.c_cc[VTIME] = 0;
+	}
 	if (!tcsetattr(term_fd, TCSAFLUSH, &t))
 		return 0;
 
+	sigchain_pop_common();
 error:
 	close(term_fd);
 	term_fd = -1;
@@ -100,6 +110,8 @@ void restore_term(void)
 		return;
 	}
 
+	sigchain_pop_common();
+
 	if (hconin == INVALID_HANDLE_VALUE)
 		return;
 
@@ -134,6 +146,7 @@ int save_term(int full_duplex)
 
 	GetConsoleMode(hconin, &cmode_in);
 	use_stty = 0;
+	sigchain_push_common(restore_term_on_signal);
 	return 0;
 error:
 	CloseHandle(hconin);
@@ -150,7 +163,11 @@ static int disable_bits(DWORD bits)
 
 		if (bits & ENABLE_LINE_INPUT) {
 			string_list_append(&stty_restore, "icanon");
-			strvec_push(&cp.args, "-icanon");
+			/*
+			 * POSIX allows VMIN and VTIME to overlap with VEOF and
+			 * VEOL - let's hope that is not the case on windows.
+			 */
+			strvec_pushl(&cp.args, "-icanon", "min", "1", "time", "0", NULL);
 		}
 
 		if (bits & ENABLE_ECHO_INPUT) {
@@ -177,10 +194,10 @@ static int disable_bits(DWORD bits)
 	if (save_term(0) < 0)
 		return -1;
 
-	sigchain_push_common(restore_term_on_signal);
 	if (!SetConsoleMode(hconin, cmode_in & ~bits)) {
 		CloseHandle(hconin);
 		hconin = INVALID_HANDLE_VALUE;
+		sigchain_pop_common();
 		return -1;
 	}
 
@@ -385,7 +402,7 @@ int read_key_without_echo(struct strbuf *buf)
 
 			ch = getchar();
 			if (ch == EOF)
-				return 0;
+				break;
 			strbuf_addch(buf, ch);
 		}
 	}

compat/terminal.h

@@ -1,7 +1,15 @@
 #ifndef COMPAT_TERMINAL_H
 #define COMPAT_TERMINAL_H
 
+/*
+ * Save the terminal attributes so they can be restored later by a
+ * call to restore_term(). Note that every successful call to
+ * save_term() must be matched by a call to restore_term() even if the
+ * attributes have not been changed. Returns 0 on success, -1 on
+ * failure.
+ */
 int save_term(int full_duplex);
+/* Restore the terminal attributes that were saved with save_term() */
 void restore_term(void);
 
 char *git_terminal_prompt(const char *prompt, int echo);